Abrading tool



March 15, 1949.

Filed Maroh 12, 1947 J. F. ElsELE 2,464,385

ABRADING TOOL 2 Sheets-Sheet 1 Y /NVENTOR John F. Eisele FlC.

M4. @www ATTORNEY March 15, 1949.y

Filed March 12, 1947 J. F. EISELE ABRADING TooL 2 Sheets-Sheet -2Patented Mar. 15, 1949 UNITED STATES PATENT OFFlCE ABRADING TOOL John F.Eisele, Pinckney, Mich.

Application March 12, 1947, Serial No. 734,138

10 Claims. l

This invention relates to abrading tools and more particularly toholders for sheets of abrasive material.

The principal object of the present invention is to provide a tool ofthe above character, means for minimizing the clogging of sheets ofabrasive material when the tool is in use.

A further object of the invention is to provid such a tool which can beadjusted to conform to curved surfaces on which the tool is used.

Another object is to provide such a tool which can be easily andeconomically manufactured.

For a thorough understanding of the invention, reference is made to thefollowing description and accompanying drawings, wherein:

Figure 1 is a side elevational view of a sanding tool embodying thepresent invention;

Figure 2 is a plan view of the base of the tool, the grip member havingbeen removed from the tool;

Figure 3 is a cross-sectional view taken on substantially the line 3-3of Figure 1;

Figure 4 is a side elevational View similar to Figure 1 showing the baseof the tool adjusted to fit a concave surface;

Figure 5 is a bottom plan View of the base; and

Figure 6 is a side elevational view of one of the clamping strips in thebase.

The tool disclosed herein is designed to hold a sheet of abrasivematerial, such as sandpaper, emery paper, or the like, while the tool isreciprocated by hand upon the surface being worked upon. The tool ispreferably connected by a flexible hose to a source of compressed air,and the tool is so designed that when thus connected, a stream ofcompressed air is continuously forced out between the base of the tooland the sheet of abrasive, thereby vibrating the latter and shakingsmall particles from the abrasive sheet, minimizing the cloggingthereof. The base of the tool is flexible, so that it can be adjusted tollt variously curved surfaces.

In general, the tool comprises a flexible base I0 on which the abrasivesheet is supported, a grip I I by which the tool may be held in the handand by means of which the sheet of abrasive is clamped to the base,mechanism l2 for adjusting the curvature of the base, and means forintroducing a stream of air between the base and the abrasive sheet.

The base I0 is formed from a plurality of relatively thin plates ofmetal I3 and lll, and a pad formed of a sheet oi felt I5 and a sheet ofrubber I6. There are two plates of metal I3, both identical. They aregenerally rectangular and each is provided at one end with an upstandingflange I'l. These two flanges are located in parallel relation andclamped against opposite faces of a metal spacer I8 which will be morefully described presently. The edges of the plate I 3 remote from theflanges Il are provided with flanges I9 of arcuate cross-section. SeeFigures 1 and 4.

The plates Ill, of which there are two, are of approximately the samewidth as plates I3, but are shorter. They are placed en top of theplates I3. An edge of each plate Il?. is provided with an upstandingflange 2Q. The flanges 20 are positioned against the flanges Il, as seenin Figures 1 and 4.

The spacer I8 is a rectangular plate of metal having a hole 2|therethrough, and a slot 22 communicating with the hole and extendingdownwardly to the lower edge of the spacer.

The flanges I 'I and 26 are 'clamped against the spacer I8 by two metalstrips 23, which are fastened in place by two machine screws 24. Thestrips 23 and flanges I'l and I8 all have holes therethrough registeringwith the hole 2I in the spacer I8. Each strip 23 is also provided with apair of laterally spaced tongues 25 struck from the metal thereof andbent outwardly and downwardly. See Figures 1, 4 and 6. A pair ofparallel slots 32 extend downwardly from the top edge of each strip 23.See Figure 6.

The felt pad I5 is cemented to the under sides of plates I3 and curvesupwardly over the flanges I9. A plurality of pieces of cord or ilexiblewire 25 are cemented to the bottom surface of the felt, as shown inFigure 5. The cords 26 are arranged so that they radiate outwardly fromthe center of the felt sheet. The rubber sheet I6 is cemented to thecords 26 and the felt I5. Since the rubber sheet i6 is thin and soft itconforms to the irregular contour of the felt and cords and produces aplurality of downwardly opening shallow channels or grooves radiatingfrom the center of the pad. A hole 27 is cut through the rubber and feltsheets to register with the slot 22 in the spacer IB.

The/grip Il is a piece ofv relatively heavy, yet somewhat flexiblemetal, bent into U-shape. See Figure 1. The extremities of the grip areflanged laterally outwardly at 28. The bight of the grip is covered witha pad 29 of soft material. In the center of the bight of the grip is adownwardly opening depression 3E). See Figure 3.

The grip is employed as a handle to be grasped by the operator of thetool. It is also used'to clamp a sheet of abrasive material 3l onto thebase. The sheet of abrasive is out sufficiently long the slot 22 in thepart i8.

to cover the under side of the base and curve over the ends of the baseinto the channels formed by the curved anges I9. The legs oi the grip il are then sprung into the channels, with the flanges 23 engaging theabrasive and clamping the same against the insides cf the iianges lil.

The mechanism l2 for adjusting the curvature of the base comprises apair of parallel arms rlhe arms 33 are attached to a pair oi thinflexible metalplatesjl of the configuration shown in Figure'Z. The armsare pivotally connected to upturned ears 35 on opposite sides of theplates M. The central portions of the arms are connected together by abolt 3i? and a spacing sleeve 31. Rigidly attached to the spacing sleeve3l and extending radially thereof is a screw 3S.

A relatively deep rectangular notchs is cut in each arm midway betweenits ends. The notches receive the anges il and 2t and the spacer I8. Theedges of the notches 39 fit into and slide vertically in the slots 32 inthe clamping strips23.

`Two coil springs 40 havingeyes lll in the ends thereof are hooked ontothe lugs 25 on the strips p23 and extend over the spacing sleeve 31. The

3B. The adjusting nuthas an elongated sleeve et,

internally threaded at its lower end, screwed thereon. The upper end ofthe sleevefl is rounded to t into the depression Preferably a largeknurled knob lle is xedly connected to the sleeve 43. Theknob #i4 has anannular iiange Ellla'held between the nut 42 and the sleeve 4E. The freeend of the screw 38 is enlarged slightly after the -nut 42 is threadedthereon to prevent removal of the latter.

A tubular couplingll having a port .te in the side thereof is insertedinto the hole El through the parts 'l, lfll andf, and securely fastenedtherein. /The port it is arranged to register with One end of thetubular coupling is closed by a suitable plug. To the other ends of thecoupling is attached an air hose 4'1 f above, the valve in the air lineopened. The

tool is then applied to the surface `to be sanded and vmanuallyreciprocated thereon, as in the case of the well known crude sandpaperblock. A stream of air under `pressure liows through the hose il ,andcoupling't, out through theport 45, slot` 22 and hole-2l. The air cannotpassthrough the` sheet of abrasive material. Therefore, it fansoutwardly between the rubber sheet i6 andthe abrasive through theshallow grooves between the ridges in the rubber sheet formed by thecords 25. In so doing it sets ip a rapid Vibration, or fluttering, oflittle magnitude in the abrasive sheet, ythereby dislodging particles ofdust abraded from the work surface, which ordinarily tend to ll thespaces between the abrasive particles on the sheet of abrasive material.

If the work surface is concave, the base can be See Figure transmittedthrough the arms 33 to the plates 34 between the center and the ends oithe base. The force is distributed quite uniformly through the plates35i and thereby produces a smooth, uniform curve in the base. The arms33 can slide np and down relative to the central rib formed of the partsll, Eil, 2li and 23, upward movement of the arms being resisted by thesprings Mi.

Ii the Werl; surface is convex, the knob 4d is retracted sdfciently torelease the sleeve 43 from the depression and the lrnob'i, sleeve i3 andscrew i@ are swung to one side, as shown in broken lines in Figure l.Since the base is flexible it can then iollow a convex surface merely byYapplying downward pressure on the grip l l.

From the foregoing' it will be seen that the 4present inventionnrotfides an abra-ding tool which be quickly adjusted to fit a plane orVarious curved su Aare". It prolonge the life of the sheets oi abrasivematerial by minimising clogging thereof. 4It can be simply andeconomically nlanni'act'ln'ed.

The scope ci the invention is indicated in the appended claires.

claim:

l. A device of the character described comprising a relatively thin,flexible sheet metal base haring a central transversely extendingupstanding rib, said rib having an air duct therein 1';- tending throughthe lower surface of ,said base centrally thereof, and means attached tosaid rib and associated with said air duct for forcing a current of vairthrough said duct out beneath said base.

2. A device oi' the character described in claim l wherein the lowersurface oi the case is `provided d dcf-"yz-Lrdly opening groovesradiating toward the edges of said base from the lower end ci said airduct.

3. A device of the character described comprising a relatively thinflexible base member, an arched relativehT id grip member attached tosaid base member in spaced zonesfadjacent two opposite edges oi saidbase member and spaced from said base member intermediate said Zones, arelatively rigid extending between said Zones and engaging said basemember at led points spaced from scnes, spring means con necting saidarms to said base intermediate the ends ci said arm and biasing said armtoward said base member, and an extensible and contractible strutconnected to said arm intermediate the ends of the latter and engagingsaid arched grip member centrally thereof.

e. A device of the character described in claim 3 wherein said strut ispivotally connected to said arm and is disengageable from said archedgrip member when said strut is contracted a predetermined distance.

5. A device of the character described comprising a relatively thinflexible base member, a relatively rigid arched grip member attached, tosaid base member in spaced sones adjacent two opposite edges oi saidbase member and spaced from `said be e intermediate said sones, a pairapart relatively arms eX- tending between said zones and engaging saidbase member at spaced points spaced from said Zones, and an extensiblestrut connected to said arms intermediate the ends of the latter andengaging said arched grip member centrally thereof.

6. A device of the character described in claim 5 wherein said strut ispivotally connected to said arms and is disengageable from said archedgrip member when said strut is contracted a predetermined distance.

7. A device of the character described in claim wherein said strutcomprises two parts connected together and movable axially of eachother.

8. A device of the character described in claim 5 wherein said arms areconnected to said base member by spring means attached to said arms andsaid base member intermediate the ends thereof, said spring meansnormally biasing said arms toward said base.

9. A device of the character described comprising a relatively thinexible base member, an arched relatively rigid grip member attached tosaid base member in spaced zones adjacent two opposite edges of saidbase member and spaced from said base member intermediate said zones, arelatively rigid arm extending between said zones and engaging said basemember at spaced apart points spaced from said zones, and a strutconnected to said arm intermediate the ends of the latter and engagingsaid arched grip member centrally thereof, said strut being extensibleand contractible whereby to vary the spacing of the central portions ofthe base member and grip member and thereby iiex said base member.

10. A device of the character described in claim 6 9 wherein said strutis pivotally connected to said arm and is disengageable from said archedgrip member when said strut is contracted a predetermined distance.

JOHN F. EISELE.

REFERENCES CITED The following references are of record in the lle ofthis patent:

UNITED STATES PATENTS Number Name Date 222,268 Gilmore Dec. 2, 1879271,222 Coffin Jan. 30, 1883 736,736 Kane Aug. 18, 1903 812,119 DensonFeb. 6, 1906 840,982 Williams Jan. 8, 1907 1,009,785 Peterson Nov. 28,1911 1,501,192 Severns July 15, 1924 FOREIGN PATENTS Number Country Date576 Great Britain J an. 8, 1912 438,824 France Mar. 25, 1912 350,391Germany Mar. 20, 1922 523,147 Germany June 1, 1929 582,349 Germany Aug.14, 1933 Certificate of Correction Patent No. 2,464,385. March 15, 1949.JOHN F. EISELE It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 1, line 5, after the Word provide insert in; column 3 line 47,for ends read end;

and that the said Letters Patent should be read With these correctionstherein that the same may conform to the record of the oase n the PatentOffice.

Signed and sealed this 23rd day of August, A. D. 1949.

[IML] THOMAS F. MURPHY,

Assistant Commissioner 0f Patents.

